
	function haslogin() {

		var xmlhttp, msg;
		if (window.XMLHttpRequest) {
			xmlhttp = new XMLHttpRequest();
		} else {
			xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
		}
		xmlhttp.onreadystatechange = function() {
			if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
				msg = xmlhttp.responseText;
				var jsonmsg = eval('(' + msg + ')');
				if (jsonmsg.states == "ERROR") {
					if (confirm("请先登录")) {
						window.location.href = "../arithmetic/登录.html";
					}
					return false;
				} else {

				}
			}
		};
		xmlhttp.open("POST", "../user/checkLogin.do", true);
		xmlhttp.setRequestHeader("Content-type", "application/json");
		xmlhttp.send();
	}